Optimization Of Submerged Fermentation And Extraction Processes Of Intracellular Polysaccharopeptide Of Trametes Versicolor

Trametes versicolor is an important medicinal mushroom. Intracellularpolysaccharopeptide of Trametes versicolor is an important bulk drug for its uses in manyaspects, such as improving immune function, protecting livers, cancer adjuvant therapyand so on. The submerged fermentation for producing mycelia and intracellularpolysaccharopeptide of Tramets versicolor has obvious advantages, such as qualitycontrolling, automation production, high production intensity and so on. It is very necessaryto screen excellent strain and optimize the fermentation and extraction processes to improvethe fermentation yield and extraction rate. Besides, the influence on the product by theprocesses should be studied. The main studies of the diploma were as follows:（1）By sequencing, matching genome ITS and18S rDNAsequences and constructing theevolutionary trees, four strains were identified as Tramets versicolor. By comparing thecolony morphology, colony mycelia average growth speed, fermentation performance and themain indicators（total sugar content, peptide content, molecular weight distribution） ofintracellular polysaccharopeptide, the strain JNPF-CV05was chosen as the ideal strain whichwas suitable for fermentation research for its excellences in colony morphology, myceliaaverage growth speed, fermentation production, batch stability and the main indicators ofintracellular polysaccharopeptide.（2）By single factor and orthogonal design experiments, the optimal fermentationmedium for mycelia and intracellular polysaccharopeptide was: brown sugar40g/L, cornpowder20g/L, trypton6g/L, wheat bran10g/L, KH2PO41g/L, MgSO₄·7H2_O1g/L, sunflowerseed oil1%（v/v）. The optimal fermentation culture conditions for mycelia and intracellularpolysaccharopeptide were: the initial pH was natural pH（about5）, rotation speed200rpm,inoculeum size15%（v/v）, temperature28℃. The biomass and intracellularpolysaccharopeptide production under optimized fermentation processes were24.12g/L and1.39g/L.Compared with production before optimization, the biomass was increased by1.2times and the intracellular polysaccharopeptide production was increased by71.6%.（3）The nature of intracellular polysaccharopeptide prepared under unoptimized andoptimized fermentation processes was studied. The total sugar contents of intracellularpolysaccharopeptide before and after optimization were55.2%and56.17%. The total peptidecontents of intracellular polysaccharopeptide before and after optimization were21.7%、28.6%. The main peak molecular weight of intracellular polysaccharopeptide beforeoptimization was1873.0kDa and the retention time of the main peak was16.1min. Themolecular weight distribution of intracellular polysaccharopeptide after optimization wasquiet different from intracellular polysaccharopeptide before optimization. The IR spectrashowed intracellular polysaccharopeptide contained pyran polysaccharide. The fermentationscarcely changed the properties of functional groups. Monosaccharide composition analysisshowed the sugar component was consisted of seven kinds of monosaccharides and glucosewas the main monosaccharide. Amino acid composition analysis showed the peptide component was consisted of18kinds of amino acid, Asp and Glu were the most abundantamino acids. Compared with intracellular polysaccharopeptide before optimization, the kindsof monosaccharide and amino acids did’t change, but the relative contents changed.（4）By single factor experiments, the optimal conditions of microwave extraction were:time2min, microwave power264W, liquid-solid ratio20:1, two times; The optimalconditions of hot water extraction were: temperature60℃, time1.5h, liquid-solid ratio30:1,two times. The extraction rate of microwave extraction method was slightly higher than thehot water extraction. The extraction rate of freeze-dried mycelia was the highest. Comparedwith hot water method, microwave extraction had significant advantages for shorter time,lower energy and less extraction solvent consumption. Besides, functional group properties ofintracellular polysaccharopeptide extracted by the two methods were similar and mainindicators were both conformed to the national quality standards.